Papua New Guinea's media watchdog has demanded an explanation for why local journalists were blocked from asking questions about West Papua during an official visit by Indonesia's foreign minister, Retno Marsudi.

Ms Marsudi has just wrapped up a three-country tour through the Pacific aimed at strengthening relations with PNG, Solomon Islands and Fiji.

Journalists in Port Moresby were told by PNG officials they were not to raise the sensitive issue of the Indonesian province, where a pro-independence movement has existed for decades.

Alexander Rheeney, the president of the Media Council of Papua New Guinea, has demanded clarification from PNG's foreign ministry.

"When you look at how both the Indonesian and Solomons government kept the media from engaging in this visit, it is something that is quite sad especially when it comes to freedom of the press.

"I'd like to think that if Indonesia really wants to get engaged with Melanesia and with the Pacific, they should open up to the media, take questions from the media, because I think that is the right thing to do."

PNG prime minister Peter O'Neill said the issue of West Papua had been discussed during Sunday's meeting with Ms Marsudi and PNG foreign minister Rimbink Pato.

"After many years of bilateral engagement, ours is a relationship where we can express our views in an open and honest dialogue," Mr O'Neill said in a statement.

"We appreciate Indonesia's understanding that our concern on this issue relates to human rights, and this is not linked to issues of sovereignty.

"I further expressed my desire for Indonesia to support the application of the Papua provinces to have membership in the Melanesian Spearhead Group (MSG)."

The MSG leaders are expected to meet to make a decision in the middle of the year.

Apart from Vanuatu, governments in the Pacific in the past have been reluctant to raise human rights issues or speak on behalf of Melanesian separatists.